A nonaqueous electrolyte battery using lithium titanium composite oxide as an active material has an advantage in that fast charge and discharge can be performed stably. In addition, such battery has longer life compared to the battery using a carbon-based material such as graphite as an active material. However, those battery using lithium titanium composite oxide as an active material generate more gas at the time of charging and discharging or during storage, as compared to the battery using a carbon-based material as an active material. In particular, a large amount of gas is generated during the initial use. In addition, a large amount of gas is also generated when the battery are stored at high temperatures. If a large amount of gas is generated, battery expand is generated. As a result, the internal resistance increases, thereby deteriorating the cycle performance.